Suburban tractor and controls

ABSTRACT

A surburban tractor having a transmission control lever moveable between park and drive positions cooperatively related to a rear pivotable deck, a starter switch, and a parking lock. The control is so structured and orientated that when in the drive position the starter switch is open, the parking lock disengaged, and the rear deck is substantially prohibited from pivotable movement. In the park position the starter switch is closed, the parking lock engaged, and the rear deck is free to be pivoted.

United States Patent 91 4/1956 Murty et a]. ..l80/69C X Halls et al. 51Feb. 6, 1973 [5 1 SUBURBAN TRACTOR AND 2,931,452 4/1960 Mackie ..l80/69c CONTROLS 3,261,422 7/1966 Jensen ..l80/69 C 3 7 96 M h 7 [75]Inventors: Lawrence M. Halls, New Holland, 329329 ll 7 uk '180/ 7Tc gi'g Seymour Lebanon Primary Examiner-Kenneth H. Betts Attorney-Joseph A.Brown, John C. Thompson and [73] Assignee: Sperry Rand Corporation, NewHol- James J. Kennedy land, Pa.

221 Filed; Oct. 5, 1970 [57] ABSTRACT [21] APPLNO': 78138 A surburbantractor having a transmission control lever moveable between park anddrive positions cooperatively related to a rear pivotable deck, a 2] US.Cl. ..l80/82, 180/111, 180/77 TC Starter Switch and a parking lock Thecomm] is so [51] Int. Cl. .......Bk 27/08 structured and orientated thatwhen in the drive posi [58] Field of Search ..l/69 C, 77 TC, 89, 90.6, ih starter wit h i open, the parking lock disen- /82 gaged, and the reardeck is substantially prohibited i from pivotable movement. ln the parkposition the [56] References cued starter switch is closed, the parkinglock engaged, an d v UNITED STATES PATENTS the rear deck is free to bepivoted.

2,740,487 3 Claims, 5 Drawing Figures SUBURBAN TRACTOR AND CONTROLSBACKGROUND OF INVENTION This invention relates to suburban tractors andmore particularly to a series of locking and precautionary devices usedtherein, and means for imposing and actuating these devices.

In the past a few suburban type tractors have employed rear pivotabledecks in order that easy access may be gained to the transmission, rearend, and other drive components for servicing and repairing. In thosetractors equipped with rear pivotable decks it has been necessary toplace the operators station atop the decks due to the limited area aboutthe rear of the tractor. Since the deck pivots back and forth, it hasbeen difficult to incorporate controls for the transmission and liftsystem within the deck and these controls have been mounted separatelyfrom the deck. The mounting of controls adjacent the deck is desirablebecause such controls are easy to reach and manipulate.

Also tractors of the prior art have included mechanisms cooperativelyinterconnected with the transmission control lever for locking thetractor when parked. The main disadvantage of the presently used parkinglocks is that they are quite complex and expensive to manufacture, thecomplexity and expense mainly being in the means for actuating thelocking mechanism.

It is therefore an object of the present invention to provide a suburbantractor with a rear pivotable deck with the transmission and lift systemcontrol levers normally extending therethrough in closeproximity to theoperator. I

Another object of the present invention is to provide means forinterlocking the deck whereby it can only be pivoted when'thetransmissioncontrol lever is in park.

A further object of the present invention is to provide a parking lockmechanism having a simple, relatively inexpensive means for actuating.

Another object of the present invention to incorporate a series ofsimple, relatively inexpensive locking and precautionary devices into asuburban tractor and to provide a common means sensitive to theoperative and inoperative modes of the tractor for actuating the lockingand'precautionary devices.

A more particular object of the present invention is to provide asuburban tractor having a starter switch and a parking lockcooperatively connected to a transmission control lever which ismoveable between park and drive positions whereby the starter switch isopen and the parking lock disengaged when the control lever is in thedrive position and wherein the starter switch is closed and the parkinglock engaged when the control lever isin the park position. i

A further object of the present invention is to provide a spring loadedparking lock that is en'gageable with a gear that is drivenly connectedto the rear wheels of the tractor.

Another object of the present invention is to provide a parking lockhaving a locking pin with spring means therearound, a housing rotativelydisposed about the locking pin and engaged with the spring means, andmeans for urging the housing back and forth alongthe longitudinal axisthereof as rotated, whereby the iongitudinal movement of the housingcauses the spring means to be compressed, therebybiasing the locking pinfor engagement with gear means drivenly connected to the rear wheels ofthe tractor.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of therear portion of the suburban tractor equipped with mechanismsconstructed in accordance with the invention.

FIG. 2 is.a plan view, on a reduced scale, of the rear deck andtransmission control lever.

FIG. 3 is a sectional view taken through the lines 3- 3 of FIG. 1showing the differential rear end, the locking gear thereof, and theparking lock in the locked or engaged position.

FIG. 4 is a detail view of the parking lock looking in the direction ofthe arrows 44 in FIG. 3.

FIG. 5 is a cross sectional view of the parking lock taken through thelines 55 of FIG. 3.

In the following description right-hand and left-hand reference isdetermined by, standing to the rear of the tractor and facing thedirection of travel.

DESCRIPTION OF PREFERRED EMBODIMENT With reference to the drawings indetail, particularly FIG. 1, a suburban tractor is indicated generallyby the numeral and includes a longitudinal chassis l2 supported by wheelmeans 14. An internal combustion engine, not shown, is mounted forwardlyon the tractor chassis l2 and is drivingly connected to a conventionaland a spur gear 20 affixed thereto. Spur gear 20 is meshed with a firstreduction gear 22 of a differential rear end 24 which will besubsequently discussed in greater detail, but, in general, thedifferential rear end axially fixed to the reduction gear 22 and meshedwith a ring gear 28 for driving left and right hand side axle shafts 30which are, in turn, drivingly interconnected with the wheel means 14. H

A control lever 32 extends upwardly adjacent the right-hand side of thechassis 12 and is moveable between park, neutral, forward, and reversepositions. Operatively connected to the control lever 32 is a cam plate34 having a generally S-shaped arc 36 therein. Confined within the arc36 is a stub shaft 38 fixed to a follower arm 40 which is connected tothe hydrostatic transmission 16. The movement of the follower arm 40, asdictated by the control lever 32 and cam plate 34, determines both thedirection and flow rate of fluid within the hydrostatic transmission 16,thereby con trolling the speed and direction of the transmission outputshaft 18. i

Mounted outwardly along the left-hand side of the rear end 24, adjacentthe reduction gear 22, is a cylindrical shaped parking lock mechanism42. The housing 114 of the parking lock 42 is rotatable about thelongitudinal axis thereof and is connected to a looped cable 44 by anear 46. The looped cable 44 extends from the parking lock 42,transversely under the tractor chassis l2, and up to fixed point 48about the righthand side of the tractor 10 in close proximity to thecontrol lever 32. Cable 44 is slidably contained within a cable housing50 which is fixed about the lower end to bracket 52 and is attached atthe upper end to a moveable arm 54 extending from the control lever 32.The bracket 52 generally extends from the park lock 42 and hydrostatictransmission 16 having an output shaft l8 24, as shown in FIG. 1,comprises a pinion gear 26 cospecifically is integrally formed withbushing 104 contained within the park lock, as best seen in FIG. 3. Toactuate the parking lock 42, the cable housing 50 causes the cable 44 tobe pushed rearwardly, rotating the parking lock counter clockwise. Insimilar manner, the movement of the housing 114 downwardly causes thecable 44 to be retracted rotating the parking lock 42 clockwise.

Continuing to refer to FIG. 1, a normally open micro switch 56 which isa part of the engine starting circuit, not shown, is particularlydisposed for engagement with the control lever 32 when in the parkposition. The contact of the control lever 32 closes the micro switch,thereby permitting the engine to be started.

With reference to FIGS. and 2 a deck 58 is pivotally secured about atransverse axis 60 to the rear of chassis 12 and movable thereaboutsfrom a normally horizontal position shown in solid lines of FIG. 1 to avertical, upright position shown in phantom in FIG. 1. As best seen inFIG. 2, the deck 58 is generally includes a medial portion 62substantially aligned with the chassis l2 and having an operators seat64 (shown in phantom in FIG. 1) fixed thereto. Extending outwardly fromthe medial portion 62, shielding the rear wheel means 14, are left andright fender portions 66,68 respectively. The front of the medialportion 62 is shaped into an inverted-U for snuggly fitting around thechassis l2 and is fixed thereto by clamp means, not shown.

A rectangular opening having a perimeter 70 is provided within the deck58, intermediately of the medial portion 62 and the right-hand fender68, for encompassing a rectangular mounting member 73 which is mountedto the right-hand side of chassis 12. A

generally Y-shaped shifting slot 72 is provided within member 73 andconfines control lever 32 therein. The control lever 32 is mounted aboutits lower end by a mounting structure indicated generally at 69 in FIG.1 which permits the control lever to move forwardly and sidewardlywithin the Y-shaped shifting slot 72. As shown particularly in FIGS. 1and 2 the control lever is moveable between a park position 74, neutralposition 75, forward position 76, and a reverse position 78. Ofparticular significance is the angle and length of extension of thecontrol lever 32 with respect to the perimeter 70 of the rectangularopening. Specifically, as seen in FIGS. 1 and 2, the control lever 32 isorientated such that in the forward, neutral, and reverse positions theupper end thereof lies in the pivotable path of the perimeter 70,thereby obstructing the pivotable movement of the entire deck 58. Thedeck as drawn in dotted lines of FIG. 1 shows this obstructionparticularly.

Now turning to FIGS. 3, 4, and 5, the differential rear end 24 andparking lock mechanism 42 are shown in detail. The rear end 24 has ahousing 80 mounted to the chassis l2 and is drivingly connected to thetransmission 16 by the engagement of spur gear 20 with the firstreduction gear 22 (FIG. 1). Referring to FIG. 3 particularly, a driveshaft 82 is co-axially secured to the reduction gear 22 and isjournalled within bearings 84. Fixed to the rear end of shaft 84 is apinion gear 86 meshed with a ring gear 88 which is fixed to a yoke-likecarrier 90. The carrier 90 is rotatively journalled within carrierbearing 92 spaced to each side thereof. Disposed within the carrier 90is a conventional differential comprised of a pair of side gears 94,each of which is drivingly connected to an axle shaft 30, and a pair ofpinion gears 96 meshed between the side gears 94 and rotatable 1 about across shaft 98, the axis of which extends normal to the axis of rotationof the side gears 94. Opposite ends of the cross shaft 98 are fixed tothe carrier 90. Spacers 100 are interposed between the axle shafts 30and the housing 80. Therefore as the carrier is rotated by t he ringgear 88, the pinion gears 96 are likewise rotated by the cross shaft 98,turning the side gears 94 and the axle shafts 30 in the process.

The parking lock mechanism 42 is mounted to the rear end housing 80,adjacent the reduction gear 22 and comprises an elongated locking pin102 moveable along the longitudinal axis thereof within a bushing 104.The inward end of the locking pin 102 includes a blunted, tapered tip106 for locking engagement with the teeth of the reduction gear 22.Biasing means in the forms of a pair of coil springs 108,110 arecircularly disposed along a segment of the locking pin 102 in end to endrelationship and confined therealong by stops 112. A cylindrical housing114 is axially aligned with the locking pin 102 and rotatable about thebushing 104. The cylindrical housing 114 has a partition or outward end116 interposed between the springs 108,110. Extending transverselythrough the cylindrical housing 114, bushing 104, and locking pin 102 isa cross shaft 118. The cross shaft 118 is fixed to the bushing 104 andextends through an open slot 120 along the longitudinal axis of thelocking pin 102. Opposite ends of the cross shaft 118 are confinedwithin axially slanted slots 122 of the cylindrical housing, shownparticularly in FIG. 4. To rotate the cylindrical housing 114 about thebushing 104 an ear 46 is fixed to the housing and connected with thelower end of cable 44.

OPERATION In order to start the tractor engine the control lever 32 mustbe in the park position such that the micro switch 56 (FIG. 1) isclosed. This particular feature gives reasonable assurance that thetractor will not be started when the transmission is in the forward,reverse, or even neutral position. But once the tractor 10 has beenstarted and the control lever 32 has been moved from the park position(FIG. 2), the deck 58 cannot be pivoted upwardly from the normalhorizontal position because the control lever 32 is so structured andoriented that it lies in the pivotable path of the perimeter 70 of therectangular opening of the deck.

Once the tractor 10 has been stopped, the control lever 32 is placed inthe park position indicated at 74 in FIG. 2. As seen in FIG. 1, themovement of the control lever 32 to the park position lifts the cablehousing 50 upwardly with respect to the fixed point 48 of the cable 44.Since the cable housing 50 is looped and the lower end thereof is fixedwithin bracket 52, the upperward movement of the housing forces thecable 44 rearwardly out of the lower end of the housing, rotating thecylindrical housing 114 of the parking lock counter clockwise. As thecylindrical housing 114 is rotated counter clockwise, the presence ofthe fixed cross shaft 118 within the axially slanted slots 122 compelsthe housing to move inwardly toward the reduction gear 22 (FIGS. 3 and4). The inward movement of the cylindrical housing 114 compresses theinward spring 108,

biasing the locking pin 102 for locking engagement between a pair ofteeth of reduction gear 22. It is possible that a single tooth may bealigned with the tip 106 of the locking pin 102 and prohibit lockingengagement. Should this occur the tip 106 would immediately lodgebetween the aligned tooth and the next adjacent tooth with the slightestmovement of the tractor since the locking pin 102 would be biasedinwardly. Once the tractor engine has beenstarted, the movement of thecontrol lever 32' from the park position to either the forward orreverse positions moves the cable housing 50 downwardly with respect tothe fixed cable point 48. The downward movement of the cable housing 50forces the cable 44 forwardly within the lower end of the cable housing,rotating the cylindrical housing 114 of the parking lock clockwise. Thecylindrical housing 114 is compelled to move outwardly from thereduction gear 22 by the presence of the fixed cross shaft 118 withinthe axially slanted slots 122 as it is rotated clockwise. As thecylindrical housing 114 moves outwardly, the outer sprin 110 iscompressed, biasing the locking pin 102 outwardlyfor disengagement withthe reductiongear 22. If the tractor l0 happens to be on an incline, theload on the reduction gear 22may tend to prohibit the ejection of thelocking pin 102 immediately upon movement of the control lever 32 fromthe park position. But once the control lever 32 is placed into gear theload is taken from the reduction gear 22 and the locking pin 102 isejected therefrom since it is biased outwardly.

The terms, upper, lower," forward, rearward etc., have been used hereinmerely for the convenience of the foregoing specification and in theappended claims to describe the present invention and its parts asorientated in the drawings. It is to be understood, however, that thesetermsare in no way limiting since the invention may obviously bedisposed in many different positions when in actual use.

The present invention, of course, may be carried out in other specificways than those herein set forth rotatably mounted thereon, power meansmounted on.

said chassis, a forward-reverse transmission drivingly interconnectedbetween said power means'and said axle means, a rear deck secured tosaid chassis and pivotally mounted about a transverse axis to swingbetween a generally horizontal position and a raised position, anupwardly extending transmission control lever mounted at its lower endon said chassis and having an upper end disposed above the rear deckwhen said rear deck is in its horizontal position, said control leverbeing moveable between park, neutral, forward and reverse positions; theimprovement comprising disposing the mounting for the control leverbelow the rear deck, and providingan opening within the rear deckaligned with the control lever mounting and encompassing said controllever, the parts being so arranged and constructed that the rear deckmay be swung from its horizontal position to a raised position above theupper end of the control lever only when said control lever is in itspark position.

2. A tractor, as recited in claim 1, wherein said con trol lever extendsthrough a shifting slot formed within a mounting member, said mountingmember being spaced to align with the opening in said rear deck whensaid rear deck assumes the horizontal position.

3. A tractor, as recited in claim 2, wherein said mounting member,control lever, and the opening in said rear deck are offset to one sideof the tractor, thereby providing convenient access to said controllever.

1. In a tractor having a chassis, axle means transversely journalled onsaid chassis and having wheel means rotatably mounted thereon, powermeans mounted on said chassis, a forwardreverse transmission drivinglyinterconnected between said power means and said axle means, a rear decksecured to said chassis and pivotally mounted about a transverse axis toswing between a generally horizontal position and a raised position, anupwardly extending transmission control lever mounted at its lower endon said chassis and having an upper end disposed above the rear deckwhen said rear deck is in its horizontal position, said control leverbeing moveable between park, neutral, forward and reverse positions; theimprovement comprising disposing the mounting for the control leverbelow the rear deck, and providing an opening within the rear deckaligned with the control lever mounting and encompassing said controllever, the parts being so arranged and constructed that the rear deckmay be swung from its horizontal position to a raised position above theupper end of the control lever only when said control lever is in itspark position.
 1. In a tractor having a chassis, axle means transverselyjournalled on said chassis and having wheel means rotatably mountedthereon, power means mounted on said chassis, a forward-reversetransmission drivingly interconnected between said power means and saidaxle means, a rear deck secured to said chassis and pivotally mountedabout a transverse axis to swing between a generally horizontal positionand a raised position, an upwardly extending transmission control levermounted at its lower end on said chassis and having an upper enddisposed above the rear deck when said rear deck is in its horizontalposition, said control lever being moveable between park, neutral,forward and reverse positions; the improvement comprising disposing themounting for the control lever below the rear deck, and providing anopening within the rear deck aligned with the control lever mounting andencompassing said control lever, the parts being so arranged andconstructed that the rear deck may be swung from its horizontal positionto a raised position above the upper end of the control lever only whensaid control lever is in its park position.
 2. A tractor, as recited inclaim 1, wherein said control lever extends through a shifting slotformed within a mounting member, said mounting member being spaced toalign with the opening in said rear deck when said rear deck assumes thehorizontal position.